<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <h1>POST请求</h1>
    <form id="form">
        <input type="text" name="name">
        <input type="text" name="age">
        <input type="text" name="sex">
        <button id="btn">提交</button>
    </form>
    <script>
        const oForm = document.getElementById('form')
        const oName = document.querySelector('#form input[name=name]')
        const oAge = document.querySelector('#form input[name=age]')
        const oSex = document.querySelector('#form input[name=sex]')
        const oBtn = document.getElementById('btn')

        oForm.onsubmit = function() {
            const nameValue = oName.value;
            const ageValue = oAge.value;
            const sexValue = oSex.value;

            const xhr = new XMLHttpRequest();

            xhr.open("POST","/adduser?a=1",true)
            
            // 请求体的数据放在send中传递
            // 因为请求体类型有很多，所以发送请求的时候一定要设置请求头的Content=Type类型
            // xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded;charset=utf-8");
            // xhr.send('name=${nameValue}&age=&{ageValue}&sex=${sexValue}')

            xhr.setRequestHeader("Content-Type","application/json;charset=utf-8")
            xhr.send(JSON.stringify({
                name:nameValue,
                age:ageValue,
                sex:sexValue
            }));

            shr.onreadystatechange = function(){
                if (xhr.readyState === 4 && (xhr.status >= 200 && xhr.status <= 299)){
                    console.log(xhr.responseText);
                }
            }

            return false
        }
    </script>
</body>
</html>